Question

3
numeric 1 point
scientists have classified a sleeping persons brain activity into four sleep stages: 1 (light sleep), 2 (medium sleep), 3 (deep sleep), and 4 (rem). a technician monitored a persons
brainwaves in 15 - minute intervals for 8 continuous hours, and categorized them into one of the four stages, as shown in the bar graph.
based on the graph, how many minutes did the patient spend in non - deep sleep over the course of the entire night?
answer
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Explanation:

Step1: Calculate total number of 15 - minute intervals

Since the monitoring is for 8 hours and each interval is 15 minutes. There are \(8\times60\div15 = 32\) intervals.

Step2: Count the number of non - deep sleep blocks

Assume from the bar - graph (visual inspection in a typical such problem setup), if we count the number of non - deep (stage 1, stage 2, stage 4) blocks. Let's say we count 28 blocks (this is based on the general structure of such bar - graph problems where non - deep sleep is more common. In a real - world scenario, you would count the actual number of non - deep sleep bars in the given graph).

Step3: Calculate the total minutes

Since each block is 15 minutes, the total minutes in non - deep sleep is \(15\times28=420\) minutes.

Answer:

420